finance/py-python-bitcoinlib: Update to 0.11.0

• Add "do-test" target to make future QA easier while I'm here.

Changelog:

• Bech32 implementation
• Segwit implementation (for P2WSH and P2WPKH transactions) and examples
• Use libsecp256k1 for signing
• Implement OP_CHECKSEQUENCEVERIFY
• Dropped Python 2.7 support